Changes in stroke risk by freedom-from-stroke time in simulated populations with atrial fibrillation: Freedom-from-event effect when event itself is a risk factor.

ABSTRACT: The risk of atrial fibrillation (AF)-related stroke is usually assessed by calculating the CHA2DS2-VASc score, the components of which are various risk factors, including prior stroke. Although prior stroke is considered the strongest risk factor, the associated risk is actually inferred. Nevertheless, it implies a "freedom-from-event effect" (FEE)-the longer a patient is stroke-free, the lower the stroke risk. Although dynamic prognostication has been applied to cancer, the FEE has been ignored in AF, probably because of methodological difficulties. We conducted a simulation study to evaluate the FEE in the risk of AF-related stroke. We modeled various populations of AF patients and simulated the development of stroke assuming a nonhomogeneous Poisson process, where the hazard depends on

SUBMITTER: Nakamizo T 

PROVIDER: S-EPMC5847231 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature